Fernando Alonso will miss the 2017 Monaco Grand Prix to race in the Indianapolis 500, McLaren have announced.
Alonso has endured a tough start to the Formula One season with reliability issues forcing him to retire in Australia and China.
The Spaniard has expressed his disappointment in the MCL32's competitiveness already and called on his team to make "big changes" to improve their fortunes.
Alonso will not have to worry about such issues in Monaco, though, after opting to skip the race to try a new challenge as McLaren return to the Indy 500 for the first time in 38 years.
McLaren's car will be run by the Andretti Autosport team with a 2.2-litre twin-turbo V6 Honda engine, with Alonso at the wheel.
"I'm immensely excited that I'll be racing in this year's Indy 500," said Alonso.
"The Indy 500 is one of the most famous races on the global motorsport calendar, rivalled only by the Le Mans 24 Hours and the Monaco Grand Prix, and it's of course a regret of mine that I won't be able to race at Monaco this year.
"But Monaco will be the only 2017 Grand Prix I'll be missing, and I'll be back in the cockpit of the McLaren-Honda MCL32 for the Canadian Grand Prix in Montreal in early June.
"I've never raced an IndyCar car before, and neither have I ever driven on a super-speedway, but I'm confident that I'll get to grips with it fast. I've watched a lot of IndyCar action on TV and online, and it's clear that great precision is required to race in close proximity with other cars on the far side of 220mph [354km/h].
"I realise I'll be on a steep learning curve, but I'll be flying to Indianapolis from Barcelona immediately after the Spanish Grand Prix, practising our McLaren-Honda-Andretti car at Indy from May 15th onwards, hopefully clocking up a large number of miles every day, and I know how good the Andretti Autosport guys are. I'll be proud to race with them, and I intend to mine their knowledge and expertise for as much info as I possibly can.
"I've won the Monaco Grand Prix twice, and it's one of my ambitions to win the Triple Crown [the Monaco Grand Prix, the Indianapolis 500 and the Le Mans 24 Hours], which has been achieved by only one driver in the history of motorsport: Graham Hill.
"It's a tough challenge, but I'm up for it. I don't know when I'm going to race at Le Mans, but one day I intend to. I'm only 35, I've got plenty of time for that."
Because both races fall on May 28 Alonso will not be on the grid in Monaco and who will replace him remains unclear.
Jenson Button could be in the frame. The 2009 world champion signed as an ambassador with McLaren for this season, but is on a driving sabbatical from driving in F1.